Exciton-Coupled Coherent Magnons

The information generated by qubits is at helium temperature and localized. Magnons that are coupled to qubits and optical photons can shuttle information created by qubits at a long distance and up to room temperature. Two-dimensional magnetic semiconductors are attractive candidates to serve as this magnon medium because they can hold both tightly-bound excitons with large oscillator strength and potentially long-lived coherent magnons due to the presence of bandgap and spatial confinement. In this talk, I will discuss the nature of magnon-exciton coupling in the two-dimensional van der Waals antiferromagnetic semiconductor CrSBr. Then, I will talk about how the exciton-coupled magnons coherently propagate in time and space. Lastly, I will discuss the implication of strong coupling between magnons (0.1 meV) to excitons (1.3 eV), and relatively long coherent propagation length (7 µm) and time (10 ns) in magnonics, quantum information science, and optoelectronics.